Overview and details of the sessions of this conference. Please select a date or location to show only sessions at that day or location. Please select a single session for detailed view (with abstracts and downloads if available).
Session 14B: Collection, Pump Stations, and Conveyance
10:30am - 12:00pm
Session Chair: Adam Crafts, Murraysmith;
10:30am - 11:15am
Cured-in-Place Pipe: - Planning for the Long Haul
Colleen Harold1, Brendan O'Sullivan2, Chris Larson3, Rob Lee2
1City of Portland Bureau of Environmental Services; 2Murraysmith; 3C&L Water Solutions; , Brendan.O'Sullivan@murraysmith.us,
Cured-in-placed pipe (CIPP) has been an established pipe renewal technology for decades. The City of Portland’s Bureau of Environmental Services (BES) has embraced the technology for use in numerous projects, including the Large Scale Sewer Rehabilitation Program. However, to some at BES, CIPP carries the stigma of a short-term fix, with no clear consensus on longevity or design-life. Currently, BES is operating under the philosophy that CIPP lasts 60 years, then requires replacement, whereas the design life of new pipe, such as PVC, lasts 120 years. When adopting an asset management approach that looks at life cycle costs, under the current BES design life assumptions, CIPP may not always be the most cost-effective solution.
But what if CIPP can be engineered to last well beyond the 60 years? How would BES approach rehabilitation if CIPP proved to be a viable technology for the long haul, particularly as the City looks to rehabilitate sewers in congested downtown streets or difficult-to-access hills on the west side?
This presentation is a collaboration between the City of Portland, one of the City’s consulting engineers, and a CIPP contractor to share data and emphasize quality control. The presentation will focus on the CIPP design equations used in North America (ASTM F1216, which are currently the most conservative in the world), and recent research by other municipalities with decades of CIPP experience has shown next to no material property degradation over time. Some aspects of flexible pipe design will be discussed.
11:15am - 12:00pm
Expedited Design for Emergency Sewer Forcemain Replacement Under the Shilshole Bay
Kristy Warren1, Robert Parish2
1Murraysmith; 2Osborn Consulting, Inc; ,
In a world of aging infrastructure, emergency utility repairs are becoming more frequent. Public agencies and their consultant teams must rely on innovation and collaboration to successfully design and deliver emergency repair and replacement projects.
When Seattle Public Utilities (SPU) discovered a pipe break in a 4.5 Million Gallons per Day (MGD) capacity sewage forcemain, they moved quickly and strategically with their consultant team to design and implement an expedited solution. The pipe break in the forcemain, which conveys combined sewage and stormwater from the Ballard neighborhood in Seattle to the West Point Wastewater Treatment Plant, was located beneath the Shilshole Waterway near the Ballard Locks. A temporary sewage bypass system was quickly installed, but with a dry weather capacity of only 1.0 MGD, a permanent solution was necessary and required with a tight schedule to replace approximately 1,200 feet of forcemain.
The forcemain and vault designs were driven by the expedited emergency schedule, but focused on minimizing the project’s impact on residents. This was a significant challenge for the project as construction would impact an arterial, regional bike trail (the Burke-Gilman Trail) as well as active railroads, both with highly engaged stakeholders.
SPU and the consultant team were in constant communication throughout the design, meeting weekly to address challenges such as limiting disruption to the trail and other major design elements, while operating with a focus on streamlining processes at every opportunity. Through this effort, the team implemented an innovative solution to install the system while minimizing impacts to the trail and rails and developed creative sequencing in order to minimize system shutdown during construction.
The Pump Station 43 emergency repair exemplifies best practices for collaborative, multi-company design teams that ensure emergency utility repair projects are safely and successfully delivered while maintaining high quality and cost-effective solutions.